Rule 1: Have fun playing!
Squint's advice is as solid as you're going to get. The only thing i'd add is, know your part, and always play the tunes like you're playing a gig in front of a live audience. That means, no stopping half-way through a number because somebody hit a clinker. It means knowing and sticking to your part no matter who falls off the train. Use rehearsals to learn how to recover from a flub -on the fly-. Don't ever -stop playing- half way through a number!
Rehearsals with the last band I worked with consisted of running through the set-list that we play on a 'live gig'. Rehearsals were always conducted as if we were playing an actual live gig. Unless the bandleader called out for something that wasn't on the set-list, we played rehearsals the same way we played the gigs, moving from one tune on the list to the next, smoothly. Everybody knowing their part, what comes next on the set-list and what to expect musically from the other guys.
Always approach rehearsal time like you're getting ready to put on a show! You are!!! You guys can horse around with each other before rehearsal and afterwards. 'During' rehearsal just have fun, concentrate and play your part to the best of your ability. If each guy is doing the same thing... it'll sound great!
John
